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Re: performance analysis model

for example :

total registed users is y, and the concurrent users is x at a time , assume x is normal distribution, then x can be denoted x = f(y),i jsut want to know the work hours(8 hours), so the concurrent users per second z = f(x, y) in the 8 hours, assume m seconds per request each user, so the Requests per second can be calculated? is it right?

Re: performance analysis model

Wow, too complicated for my tiny brain... [img]images/icons/smile.gif[/img] But sisnce I test Aplications all the time, I'll tell what I do.

1. I don't care much about Y, only about X.
2. I try to estimate how much time each real user spends between requests. In my current scripts, I assume that the user moves as fast as he can to reach the Report (or other application) he wants, than waits 10-20 seconds after the Report is generated.

To sum it all up, I don't care much for the number of Hits Per Second, I simply try to emulate user behavior as accurately as I can. My current HPS, btw, stands on 0.5-0.75 per VUser.
Hope this helps.

Re: performance analysis model

Rayn,
Your calculations look pretty close. However, if you have empirical data, use that.

Things you need to keep in mind:
- First, how many users will be registered/connnected/logged in to your system at once. These connections can use resources and should be taken into account.
- Second, how many of those users are actually doing something at the same time.
- Third, how long do their actions take.
- Fourth, what is the think time between their actions.

Unless you have a really good model of your users' behavior, I would suggest that you look at whatever production logs and emulate what they're really doing.

I would also suggest that, if you haven't already, you take a look at Scott Barber's website, www.perftestplus.com. He's got a good series of articles entitled User Experience, Not Metrics.
Gook luck!
Nate

Re: performance analysis model

thx, every body

I also know use empirical data , but I'm a freshman in test, and the project is under developing. I don't know "how many of those users", "how long do their actions take", and so on. So I have to assume, to estimate. Maybe it's not a good idea. So here is a question, what should to do first like my situation? Thanks!

Re: performance analysis model

Rayn,
Have marketing or your business users give you requirements. Then, check the requirements for reasonableness. Then, test to the requirements.

Somebody, somewhere had to establish requirements around which your system was built. Hopefully, the requirements were written down and saved. Check with the business side (preferably), your engineers, architects, or developers.
Nate